Re: Helo greylisting?

From: Cami (no email)
Date: Mon Aug 01 2005 - 02:39:37 EDT

  • Next message: jay alvarez: "LDAP lookup question(are accounts still need to be present in the system?)"

    Wietse Venema wrote:
    > Cami:
    >
    >> Tony Earnshaw wrote:
    >>
    >>> Ok, it might happen once or even twice if a mailadmin discovered that
    >>> he'd made a mistake.
    >>
    >> This appears to not be a mistake of any kind. You get
    >> MTA's that are on roaming/floating ips. In the tests
    >> done on my previous mails, legit/genuine MTA's appear
    >> to do this very little though.
    >
    > It may be possible to allow for variation in the host part of
    > host.example.com, and to allow any HELO name that resolves to
    > the client IP address or its /28 block, and..., and...

    Looking further at overnight results, I'm not sure that
    is warranted: (these are hosts that bypassed all UCE
    restrictions+greylisting):

    +-----------------+-------------------------------+------+
    | _host | _helo | scnt |
    +-----------------+-------------------------------+------+
    | 64.56.232.187 | gaydemon.tv | 4 |<- 1
    | 202.82.238.6 | balance-001.com | 3 |<- 2
    | 202.188.0.162 | av4.tm.net.my | 3 |<- 3
    | 199.185.220.223 | priv-edtnes27.telusplanet.net | 3 |<- 4
    | 218.80.213.213 | gstcon | 3 |<- 5
    | 210.243.166.66 | ep14.udnpaper.com | 3 |<- 6
    | 200.59.148.41 | mail2.nuujho.com | 3 |<- 7
    | 216.221.81.25 | fep3.cogeco.net | 3 |<- 8
    | 64.59.134.9 | pd6mo2no.prod.shaw.ca | 3 |<- 9
    | 62.112.145.189 | aroundaboutcars.com | 2 |<- 10
    +-----------------+-------------------------------+------+

    1-> spam, not on any rbl, not caught by SA
    2-> spam, not on any rbl, 95 spam caught by SA, 1 slipped through
    3-> ham, not on any rbl, 0 spam, 34 ham, helo's include:
    +---------------+-----------------+
    | _host | _helo |
    +---------------+-----------------+
    | 202.188.0.162 | av4.tm.net.my |
    | 202.188.0.162 | ipop2.tm.net.my |
    | 202.188.0.162 | ipop9.tm.net.my |
    +---------------+-----------------+
    4-> ham, not on any rbl, 0 spam, 15 ham, helo's include:
    +-----------------+-------------------------------+
    | _host | _helo |
    +-----------------+-------------------------------+
    | 199.185.220.223 | priv-edtnes27.telusplanet.net |
    | 199.185.220.223 | priv-edtnes28.telusplanet.net |
    | 199.185.220.223 | priv-edtnes51.telusplanet.net |
    +-----------------+-------------------------------+
    5-> spam, listed on 3 rbl's, 5 spam caught by SA, none passed
    6-> ham, not on any rbl, 10 ham, 1 spam, helo's include:
    +----------------+-------------------+
    | _host | _helo |
    +----------------+-------------------+
    | 210.243.166.66 | ep14.udnpaper.com |
    | 210.243.166.66 | ep16.udnpaper.com |
    | 210.243.166.66 | ep17.udnpaper.com |
    +----------------+-------------------+
    7-> spam, listed on 4 rbl's, 4 spam caught by SA, none passed
    8-> ham, not on any rbl, 20 ham, 0 spam, helo's include:
    +---------------+-----------------+
    | _host | _helo |
    +---------------+-----------------+
    | 216.221.81.25 | fep3.cogeco.net |
    | 216.221.81.25 | fep4.cogeco.net |
    | 216.221.81.25 | fep6.cogeco.net |
    +---------------+-----------------+
    9-> spam, listed on 2 rbl's, 25 spam caught by SA, 5 passed
    10-> spam+ham, not on any rbl, 39 spam caught by SA, 23 passed

    So its roughly 50/50 spammers and legit hosts who change their
    helo information and still make it past all the restrictions.
    Of the legit hosts, none of them appear to use more than 3
    unique helo's.

    Cami


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